菜鸟python---小数据池

== is id

== 判断两个值是否相等

a = 10
b = 10
print(a == b)



lst = [1,2,3,4]
lst1 = [1,2,3,4]
print(lst == lst1)

is -- 是

a = 10
b = 10
print(a is b)

代码块：一个py文件，一个函数，一个模块，终端中每一行都是代码块
int，str，bool

int：-5 ~ 正无穷
    a = -6
    b = -6
    print(a is b)

    a = 1000
    b = 1000
    print(id(a),id(b))
    print(a is b)

str：
    字符串:
      1.定义字符串的时候可以是任意的
      2.字符串(字母,数字)进行乘法时总长度不超过20
      3.特殊符号(中文,符号)进行乘法的时候乘以 0 或 1

        a = "asdfasdfa22143df21af啊发生的vuwqtavuiqf！54人24215124"
        b = "asdfasdfa22143df21af啊发生的vuwqtavuiqf！54人24215124"
        print(a == b)
        print(a is b)

        a = "alee" * 6
        b = "alexe" * 6
        print(a == b)
        print(a is b)

        a = "你好啊" * 1
        b = "你好啊" * 1
        print(a == b)
        print(a is b)

bool:
    True,False

is 判断的是两边的内存地址是否相同

小数据池,代码块同在的情况下先执行代码块

小数据池 -- int,str,bool
    int：-5 ~ 256
    a = 1000
    b = 1000
    print(a is b)

    str:
        1.字母,数字长度任意符合驻留机制
        2.字符串进行乘法的时候总长度不能超过20
        3.特殊符号进行乘法的时候只能乘 0

        a = "asdfasdfasdfsad12341123123121wef214afsda"
        b = "asdfasdfasdfsad12341123123121wef214afsda"
        print(a is b)

        a = "你好啊" * 0
        b = "你好啊" * 0
        print(a is b)

驻留机制: 节省内存空间,提升效率(减少了开辟空间和销毁空间的耗时)